British Prime Minister David Cameron arrives to take part in an EU summit focused on the common security, Defence policy and Economic and Monetary union, in Brussels on December 19, 2013. The European Union took a historic leap towards greater integration just hours ahead of a summit today, with a deal on a banking union to prevent a re-run of the eurozone's recent crisis. AFP PHOTO / THIERRY CHARLIER (Photo credit should read THIERRY CHARLIER/AFP/Getty Images)

David Cameron will pledge Britain's full support for continued EU expansion today - but with tougher rules on migrants' financial benefits and rights when taking advantage of the free movement membership brings.

Two days after announcing new national restrictions to stop immediate benefit claims when UK borders are opened to Romanian and Bulgarian immigrants from January 1, the Prime Minister is seeking support from an EU summit in Brussels for his concerns about the impact of current and future enlargement of the union.

The controversial move has no wider backing from other member states for the moment and comes as the EU is extending its enlargement ambitions.

Member states have agreed to start the EU accession process with Serbia next month and are discussing possible moves to grant Albania "candidate status" now - the first step on the long path to full EU membership - or wait until next June.

The UK is one of the staunchest supporters of continued expansion, not least because a larger EU dilutes the impact of the existing federalist hardcore. But it is also the most outspoken about the risk of unfettered access for migrants.

Mr Cameron wants tougher membership conditions for the latest hopefuls and favours postponing talks with Albania for six months to enable the country to start initial reforms to make the country more compatible with its possible future union partners.

And if his colleagues raise the issue of the British benefit measures to deter migration by Bulgarians and Romanians from January 1, Mr Cameron will press the case for reconsideration of current EU rules - suggesting a new criteria by which citizens of newly-added member states would not receive full rights to live and work elsewhere in EU until their national prosperity had reached a certain level.

A Downing Street source said: "You can expect the Prime Minister to use it (the summit) as an opportunity to reiterate his concerns. He will be talking about some of the issues on his mind and his priorities. This is about getting the debate going. You can expect the PM to make clear his view and to put markers down."

But no detailed discussion is likely and Mr Cameron is unlikely to find many allies for curbing the current advantages of EU freedom of movement which membership brings.

The European Commission has already launched an investigation into whether the new national benefits restrictions Mr Cameron is introducing from January 1 are in line with EU law.